A 2 kg ball rolls from rest from point A on a frictionless track ABCD, as shown below. The horizontal section, BC, of the track is 5 cm above the ground. The ball reaches point D, 30 cm above the ground, at a speed of 1,71 m∙s-1.
5.1 Write down ONE term for the following statement:
The sum of gravitational potential energy and kinetic energy (1)
5.2 Calculate the:
5.2.1 Mechanical energy of the ball at point D (4)
5.2.2 Initial height h of the ball at point A (3)
5.2.3 Speed of the ball while it moves between point B and point C (3)
5.3 The 2 kg ball is now replaced with a 4 kg ball.
How will the speed of the 4 kg ball compare to the speed of the 2 kg ball at point D? Choose from GREATER THAN, SMALLER THAN or EQUAL TO. Give a reason for the answer. (2)